Why Sleep Studies Are Critical for 3-Year-Olds with Down Syndrome
All children with Down syndrome should undergo polysomnography (sleep study) by age 3-4 years, regardless of whether parents report sleep problems, because obstructive sleep apnea is present in 57-80% of these children and parental observations are unreliable predictors of disease severity. 1, 2
The Evidence-Based Rationale
Extremely High Prevalence of Sleep-Disordered Breathing
Down syndrome is specifically identified as a complex medical condition requiring mandatory polysomnography before any surgical intervention for sleep-disordered breathing. 1
Studies demonstrate that 57% of children with Down syndrome have abnormal polysomnography results with confirmed obstructive sleep apnea syndrome, and when including elevated arousal indices (indicating increased work of breathing), this rises to 80% of children. 2
Even among children whose parents reported no sleep problems, 54% had abnormal sleep study results, while conversely, only 36% of children whose parents reported problems actually had abnormal studies. 2
Anatomical and Physiological Risk Factors
Children with Down syndrome have multiple anatomical features that predispose them to sleep-disordered breathing, including midface hypoplasia, relative macroglossia, adenotonsillar hypertrophy, hypotonia, and craniofacial abnormalities. 3, 4
The prevalence of obstructive sleep apnea in this population is 66.4%, with younger age paradoxically associated with more severe disease. 1
Critical Safety Implications for Anesthesia and Surgery
Children younger than age 3 with documented obstructive sleep apnea on polysomnography require mandatory inpatient overnight monitoring after tonsillectomy due to increased risk of postoperative respiratory complications. 1
Polysomnography results must be communicated to the anesthesiologist prior to induction of anesthesia for any surgical procedure in children with sleep-disordered breathing. 1
The ability of polysomnography to predict postoperative complications in children with Down syndrome remains an active area of research, but the high-risk nature of this population is well-established. 1
Why Clinical Assessment Alone Is Insufficient
Poor Predictive Value of Symptoms
A well-designed screening questionnaire with good psychometric properties (Cronbach alpha of 0.87) demonstrated limited predictive value with an area under the curve of only 0.497 for detecting moderate to severe OSA in young children with Down syndrome. 5
Clinical diagnosis of sleep-disordered breathing in children is a poor predictor of disease severity, making objective testing essential. 1
Parents' impressions of sleep problems correlate poorly with polysomnography results—69% of parents reported no sleep problems despite more than half having abnormal studies. 2
Multiple Types of Sleep Disturbances
Beyond obstructive sleep apnea, children with Down syndrome experience high rates of non-respiratory sleep problems including difficulty going to sleep independently (45%), restless sleep (76%), night-time waking (24%), and bedtime resistance (22%). 6
Central sleep apnea and nocturnal hypoventilation are also common, with hypoventilation occurring in more than 22% of patients. 1
Impact on Morbidity and Quality of Life
Developmental and Cognitive Consequences
Sleep disturbance is particularly common in children with developmental disorders including Down syndrome and can significantly affect both child and family quality of life. 3
Successful treatment of sleep disorders can be expected to alleviate significantly the difficulties of both child and family. 3
Cardiovascular and Systemic Effects
Sleep-disordered breathing in children with Down syndrome is associated with higher mean systolic blood pressure, impaired left-ventricular diastolic dysfunction, and pulmonary hypertension. 1
Low baseline oxygen saturations, central apnea, and nocturnal hypoventilation correlate with pulmonary hypertension development. 1
Practical Implementation
Timing and Type of Study
Baseline polysomnography is recommended in all children with Down syndrome at age 3-4 years. 2
Laboratory-based polysomnography should be obtained when available, as it is the gold standard for objectively assessing sleep disorders. 1
Treatment Implications
Contrary to popular belief, more than half of children with Down syndrome demonstrate satisfactory adherence to respiratory support including CPAP therapy. 1
CPAP adherence in children with Down syndrome is actually higher than in children without cognitive impairment, with 75% showing good tolerance and 58.7% experiencing symptomatic improvement. 1
Even after adenotonsillectomy, 79% of children with Down syndrome referred for sleep problems had undergone previous ENT surgery, yet 61% still had obstructive sleep apnea, indicating that surgery alone is often insufficient. 6
Common Pitfalls to Avoid
Never rely on parental report alone to determine whether a sleep study is needed—the correlation between parental impressions and actual sleep pathology is poor in this population. 2, 5
Do not assume that absence of snoring or witnessed apneas rules out significant sleep-disordered breathing. 2
Avoid delaying polysomnography until after adenotonsillectomy, as preoperative assessment is critical for perioperative risk stratification and management planning. 1
Do not use screening questionnaires as a substitute for objective sleep studies in children with Down syndrome—they lack adequate predictive value. 5